Cross-scanning optical coherence tomography angiography for eye motion correction

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Optical coherence tomography angiography (OCTA) is crucial for visualizing retinal vasculature.
• Eye motion during OCTA acquisition causes artifacts, degrading image quality and hindering clinical interpretation.
• Existing motion correction methods often require external eye-tracking systems or additional scanning time.

Purpose of the Study:

• To introduce a new cross-scanning OCT (CS-OCT) system for effective correction of eye motion artifacts in OCT angiography.
• To demonstrate motion correction within a single volume scanning time without supplementary eye-tracking hardware.

Main Methods:

• A dual-illumination CS-OCT system was designed using two orthogonally polarized beams performing simultaneous, perpendicular raster scans.
• A polarization delay unit enabled acquisition of two orthogonally polarized interferograms using a single detector.
• A motion correction algorithm was developed to remove artifacts by utilizing orthogonal scan data and nonrigid registration.

Main Results:

• The CS-OCT system successfully acquired two cross-scanned volume datasets affected by motion in orthogonal directions.
• The developed algorithm effectively corrected motion artifacts in the slow axis of each angiogram.
• A motion-corrected angiogram was generated within a single volume scan, demonstrating the system's efficiency.

Conclusions:

• The proposed CS-OCT system provides a robust solution for correcting eye motion artifacts in OCT angiography.
• This technique enhances image quality and diagnostic accuracy without the need for additional hardware or prolonged scanning.
• CS-OCT represents a significant advancement for in vivo retinal imaging and clinical applications.